#encoding=utf-8
from tkinter import *
from tkinter.filedialog import *

root=Tk()
root.geometry("400x100")

def test1():
    # f = askopenfilename(title="上传文件", initialdir="/Users/graceli", filetypes=[("视频文件", ".mp4")])
    # show["text"] = f

    with askopenfile(title="上传文件",
                     initialdir="d:", filetypes=[("文本文件", ".txt")]) as f:
        show["text"] = f

Button(root, text="选择编辑的视频文件", command=test1).pack()

show = Label(root, width=40, height=3, bg="green")
show.pack()